(Pone seram - “put up the bar” is equivalent to “bar the door/lock her in")
Though in modern times the quote is applied to corrupt, unaccountable or incompetent organizations/government institutions, the original context is far more earthy. The poet is complaining about the morality of women: Even if you put guards on your adulterous wife, she is cauta (not “cautious"; “wily” is probably better here) and so she incipit her seduction with them!